ibclogo XVI International Botanical Congess

Abstract Number: 6133
Poster No. = 2525


PHYLOGENY OF TAXACEAE AND CEPHALOTAXACEAE GENERA INFERREDFROM CHLOROPLAST MATK GENE AND NUCLEAR RDNA ITS REGION


1Y Cheng, 2R. G. Nicolson, 3K. E. Tripp3, and S-M. Chaw2, 2IBAS, Taipei, 3Botanic Garden, 1Smith College, MA


Cp matK gene and nr ITS sequences were determined for all taxad genera, monotypic Cephalotaxaceae and representatives of other conifer families. Analysis using either the KA sites or the deduced amino acid sequences of matK genes strongly indicate that taxad genera and Cephalotaxaceae are monophyletic. Cephalotaxus is basal to taxad genera, in which two clades, Torreya, Amentotaxus and Taxus, Pseudotaxus, Austrotaxus are resolved. In Taxeae Austrotaxus is the first to branch off. Analyses of ITS sequence data corroborated the topology of the matK gene tree. These results refute the views that Cephalotaxaceae has no alliance with Taxaceae, and that the taxad genera are paraphyletic. We estimated the divergence time between taxads and Cephalotaxus to be 149-179 Myr ago.

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